1. Field of the Invention
The present invention relates to a liquid crystal optical device which produces an optical response by the effect of spontaneous polarization of this device.
2. Related Background Art
Ferroelectric liquid crystals (FLC), which are liquid crystals having spontaneous polarization, are being noticed because of their high response speed and excellent memory effect, and are being developed vigorously as materials for use in display devices, light valves and so forth. In fact, various devices are available which utilize the superior characteristics of ferroelectric liquid crystals, such as a light shutter array, highly fine display device by a simple matrix drive, and light valve combined with a photo-conductor and exhibiting high recording density. Furthermore, ferroelectric liquid crystal, driven by an active matrix drive system using thin-film transistor (TFT), is used in display devices which displays dynamic images. These characteristics of ferroelectric liquid crystals are detailed in, for example, U.S. Pat. No 4,840,462 and Proceeding of the SID, Vol. 30/2, 1989 "Ferroelectric Liquid Crystal Video Display".
A problem, however, has been encountered in that liquid crystal optical devices using ferroelectric liquid crystals cannot provide good gradation of display.